According to another forum that I'm on the extra costumes are paid dlc. The only ones we get are the pre order costumes and the ones that are already in the game...Rebecca Cowgirl, Leather Outfit and Billy Suit

Nah, i just kidding, unreleased shit doesn't count, but a lot of people love to count 1.5 as a legit game though.

To be fair, 1.5 was still fully playable despite being incomplete. Not sure if that's the case for RE0 N64, the RE Wiki Mass would probably know.

Since I was summoned...

From what I've read the game wasn't close to even 50% before it was rebuilt. Again. What I mean is that while developing the game they actually started from scratch multiple times because of hardware problems etc. They did have multiple endings planned and in one interview the director of the game said "In the prototype you could clear the game as long as either Rebecca or Billy was alive" but I think by that he meant the hypothetical finished version of it.

Resident Evil Zero HD sells over a million copies. It has sold thus far 1.1 million,coming close to its original sales on the Gamecube wth 1.25 million. So basically Capcom managed to sell this game twice to almost all who originally bought it, which is a good thing (sales wise) considering most only got this game as a digital download. It's the lowest selling RE (in the over-a-million department) but it still managed to get over the hump of one million nicely. And since it is still a fairly recent release, I'm sure the sales will keep slowly rising, especially when the game eventually goes on a sale on Steam. As a comparison, the remastered remake sold 1.3 million units.